1. Field of the Invention:
The present invention relates to radar systems. More specifically, the present invention relates to direct, two-way radar data links.
While the present invention is described herein with reference to an illustrative embodiment for a particular application, it is understood that the invention is not limited thereto. Those of ordinary skill in the art and access to the teachings provided herein will recognize the additional modifications, applications and embodiments within the scope thereof.
2 . Description of the Related Art:
Conventional two-way, continuous data links optimize midcourse guidance to direct a missile from a launch aircraft to the vicinity of a target. Some data links provide for a missile guidance system that not only enables the missile to receive messages from the aircraft but also enables the missile to communicate messages back to the aircraft.
Prior techniques for aircraft-to-missile communication include fiber optic guided and wire guided systems. However, both of these techniques have a payout that is too slow for the environment of modern high speed aircraft.
Radar based data links obviate the payout problem. As many aircraft have a preexisting radar onboard for fire control (FC), such systems have been considered for data link applications as well as fire control. In conventional airborne FC radar, a mechanically steerable array is used for missile guidance and communication. Two significant limitations of mechanical scanning antennas relate to the narrow beam and the high inertia associated therewith. Both of these limitations affect the ability of the aircraft to communicate effectively with the missile.
Generally, these antennas transmit a relatively narrow beam. As the mainlobe of the beam must generally be positioned at the target, the inertia associated with the antenna makes it virtually impossible for the antenna to be switched simultaneously from being aimed at the target to being aimed at the missile.
Thus, a conventional FC radar antennas can generally only transmit data link messages to the missile through the sidelobes. However, the sidelobes are typically weak compared to the mainlobe. Hence, the associated limited level of the sidelobes tends to limit the operating range of the data link. This is especially problematic when the target is attempting to jam the radar or when low power radar transmission is used to minimize the probability of intercept.
Thus, there clearly exists a need in the art for a missile guidance system which uses a missile with a low power transmitter and is able to not only receive data from the FC radar but is also able to communicate therewith.